Production of low aniline point oil



NOV. 23, E v MA1-HY PRODUCTION o? Low ANILINE: Pom" oIL Filed Dec. 22. 1949 KE'Y HMM v ATTORNEYS United States Patent@ PRODUCTION OF LOW xAN'ILINEPOINT OIL Eugene V. Mathy, Bartlesville, Okla., assigner-to Phillips This invention relates to the production of oils of specific aniline point. A more specific aspect of this invention relates to an economical process-for vreduc: ing the aniline'point of an aromatiehydrocarbon on orxin other words increasing the aromaticity ofthe oil. A preferred embodiment of this invention relates to the production of an aromatic hydrocarbon feed of opti mum aniline point for use in the production of furnace black, from an oil of too high aniline point.

Furnace black is one of two types of carbon'black produced in considerable quantity today, the other'being channel black. The vmethods of manufacture of each is considerably different'frorn the other as are the prop# erties of the products. Channel blackis produced by burning natural gas in a great number of small burners' and recovering the carbon black so produced by depositing same on a metal channel suspended just above each burner. Furnace black. is produced by burning hydrocarbons ranging from methane to asphalt with an insuicient quantityof oxygen for complete combustion, in large refractory-lined furnaces. The carbon formed by the decomposition ofthe feed iscollected-in man-y waysl such as by water spray, electrical precipitators, andcy# `clone separators.

The Vcharacteristics'of the blacks'produced bythe two processes .are different: thel furnace blackbeing higherl inixed carbon, lower in'volatile matter, less hydrophilic. In addition, furnace-black is alkaline witha pH running as 'high as l0 while channel black is acid having a pH` generally in the range of v4 to 5` or less, and the colorV of furnace black is generally lighter than that of channelY black.

Furnace black has a multitude of uses in industry, prob# .ably the most extensive of whichis in the manufacture of products such as tires fromV natural and synthetic rubbers.. Other uses are in pigments, carbon paper, typef writer ribbons, printing inks, roofing compounds, metal:

coatings, extenders'for plastics, and as replacements for lamp black and bone black.

Many'types of oils have been used in theeproduction of furnace carbonv black, and it has been foundithat oils of certain character provide better carbon bla-ck products.

than others. It has been found that a veryidesirable qualityof furnace black may be produced'when an'oil feed is used having an aniline point inlthe'range of 25. to"65 F. and that such'black may be produced in" high.

yield.

Aniline point as referred to herein is merely an. indication'of the aromaticity` of an oil and is determined` by` admixing equal quantities of aniline and the oilto be tested and determining the rninimurn.equilibrium solution temperature, i. e. the temperature vatwhich'the aniline and oil form separate phases. the aniline point.

An object of this invention is to provide an k.improved process for the productionofa specific aniline'point oil.

Another object of this` invention isto provide an economical process for the manufacture of a specic. aniline.

point oil from an oil of higher aniline point;

Another object is toincrease the aromaticity of a hy,- drocarbon oil.

Another object is to provide an oil for the manufa.

ture of carbon black.

Another object is to increase the yield. of oil ofa particular aniline point.

. Stilly another object isv to providera process. for` the'.

This temperature is. calledv ice 2. manufacture of an oil having an optimum: anilinepoint for. use in the manufacture offurnace blacks.

Other/objects? and advantages of this inventionwill be apparent'to one skilled inthe. art from the accompany--v ingv disclosure and discussion.

I have discovered an improvedand economical process v. for obtaining'an oil offthe desired aniline point, i. e. desired -aromaticity, suitable. for: use as feed to carbon' black manufacturing. processes,i particularly furnace black manufacture, in yields. considerablygreater.v than hereto@M fore obtained...

In. accordance with my processV an oil of an aniline point'` higher thanrthatdesired for: use inrthe manufacture ofA furnace. black, .such as a .cracked gas oil, is liquid-liquidy solventiextracted. to' provide.l anextract of low. aniline point (high aromaticity) and. a raffinate of high anilinepoint.(low-aromaticityyl Suitable solventsfor such an extraction are: furfuraL. methyl acellosolve, nitrobenzene; liquid vsulfur dioxide, and other known selective solvents, furfuralusually being preferred.. Obviously, it is within theE scope of theinvention. also tol use mixtures ofthesesolvents. The lextract. phase of low-aniline point is treated to. remove thel solventand is then blended back with a portion. ofthe unextractedfeed thereby increasingthe aromatic ycontentof the feed oil and reducingl the overall' aniline point to' within the desiredy range for furnace blaclcmanufacture. Usually this aniline point range is between .25 -and .65 F., however it may be-higher o1" lower: than this. The upper limit may generally be about F., but the lowerf lim-it is only-restricted by eco-VY nomics.. This latter limit-depends on where ythe highest price maybe obtained for `the oil, i. e., by turning it intov carbon black or into some other product.

By practicing this -processonly a-portion of the high aniline point materiahotherwise vsatisfactory as a furnace black: feed', is treated 'in' the extraction zone. This is a very'denite advantage over the vtreatment of all of the feed stockfor `carbon blackmanufacture, particularly becausethe size ofthe treating equipment maybe considerablyreduced, thei'solvent requirements are less# cned, the energy expended for heating, cooling and the like. is considerablyfredueed, and yet ya greater quantity of proper aniline point oil is obtained.

Duet to the rather high freezing point'of aniline,-those aniline points below about'ZS" F. arenot satisfactory. Therefore the. aniline point of the oil produced in the example rwas determined by interpolation of the yfurfural.v point, which has been foundr'to' correlate Vwell with theV aniline peint in a straight' linerelationship. The following. .equation-:represents the method'forearriving atthe; aniline point of an oil by determining rst the furfural' AB designates aniline point, and-.FP designates furfuraly pomt.

In a preferred embodiment of Vthis invention the railinate phase, that is, the gas oilof high aniline point, is passed to. solventrem-ovalsandisrecovered therefrom for useas. a ycrackingy feed, forl burning oil, for. dieselfuel; or for other. purposes requiring an oil of low aromaticity.`

Ihave-fu'rther found thatl the aniline point of thezextract.A oil will be decreasedwitrr decreasing temperatureof extraction, the solvent to oil ratio remaining ,constant,. land will also. be decreased when thesolventV to oil ratio is decreased, the` temperature remaining thesame.- This is apparently due to the lfact that lessparainic materialk isdissolved with the'aromatic-compounds.

Usually, I prefer to feed a cracked-gas oil boil-ingxin the range of, say, 450 to 750 F. and having an aniline point in the range of 1-25"to 160 F. to the extraction Zone. and-to. blending with the extract. When using furfural as the .-solvent,` ratios of solvent to feedfare preferably in the range of 0.5 to-S voiumes pervol'urne while' theoperating temperatures of. theextracti-on zone.` lare maintained .in the` range of 50 toi. F; Suitablepres.- sures are those which will'maintainthe oil and solvent in liquid phase. Operating under these conditions an extractf oil havingY an aniline point between .-75 and +205" F. is-produced.. Suitablevconditions for other Vsolvents 'will 'readily'V 'ber-determined. by 'those-skilled in the art. Any suitable contacting or extraction chamber may be used, in the practice of my invention, however, I find that most satisfactory operation may be had by using countercurrent extraction chambers arranged in either single-stage or multi-stage.

A more full understanding of my invention may be had by referring to the attached drawing which is a schematic flow diagram of a preferred embodiment of my invention. Valves, pumps and other conventional equipment have been left out of the drawing for the sake of simplicity, however, the incorporation of such equipment in a plant process is well within the skill of the art.

Refer now to the drawing. A cracked gasoil or similar feed of low aromaticity and moderate to high aniline point is passed via line to extraction zone 11 where it is contacted in countercurrent relationship with an extractive solvent introduced via line 12. The extract phase which is highly aromatic is removed from zone 11 and passed to solvent removal zone 1S via line 17. In Zone 18 the solvent is removed from the extract, such as by stripping or by the use of a secondary solvent for the extract in known manner, and is recycled via line 19 to line 12 through which it is passed back to the extraction zone. The solvent-free extract is then removed from zone 18 via line 20 through which it is passed, along with a suitable volume of cracked gas oil such as that fed to extraction zone 11, which is passed to line 20 through line 21. The admixture of the low and high aniline point oils in line 20 may be thoroughly acomplished by turbulent iiow or by passing same to mixing zone 22 equipped with any suitable mechanical mixing device. The blended oil of desired aniline point is removed from mixing zone 22 via line 23 and is passed therefrom to furnace black manufactuer or other suitable use.

The ratinate phase in extraction zone 11 is removed therefrom via line 13, and is passed to solvent removal zone 14. Here again, the solvent may be removed from the oil by stripping or by the use of secondary solvents or other means, which processes are well known to those skilled in the art. The solvent Withdrawn through line is also recycled to extraction zone 11 via lines 19 and 12. The raffinate oil which is of high aniline point is passed from solvent removal zone 14 via line 16 to storage or to such processes as hereinabove enumerated or to other suitable use. Make-up solvent for the extraction f tle cracked gas oil is supplied to zone 11 through ine 2.

By so operating my process I have found that a higher yield of oil of the desired aniline point is obtained than would have been obtained had the total gas oil been extracted to produce an extract oil of the same aniline point. In addition a smaller quantity of oil is processed and a smaller amount of solvent is necessary for use in the extraction. Consequently, a further saving in equipment is effected.

Advantages of this invention are illustrated by the following examples. The reactants and their proportions, and other specific ingredients are presented as being typical and should not be construed to limit the invention unduly.

Example I A 150 F. aniline point cracked gas oil was extracted to yield a 60 F. aniline point extract. 'Ihis extract was blended with a portion of the original cracked gas oil to produce a 50 F. aniline point product. The yield of 50 F. aniline point oil was 33 volume per cent based on the total original oil used.

In a comparative operation, another portion of the 150 F. aniline point cracked gas oil was extracted to produce directly an extract oil of 50 F. aniline point. The yield of this extract oil was 29 volume per cent based on the oil treated.

Example II A 150 F. aniline point gas oil is extracted at a solventto-oil ratio of 2 to yield 20 F. aniline point extract. This extract is blended with a portion of the original oil to produce a 50 F. aniline point oil in a 29.5 per cent yield. Extraction of the original oil to 50 F. aniline point produces only a 27.5 per cent yield.

The conclusion which may be drawn from these two xamples is that the lower the aniline point to which a ortion of the oil is extracted before blending with unxtracted oil, the greater will be the yield of the desired 4 aniline point oil over the yield which would have been obtained by direct extraction of the total oil.

Although this process hasVK been described and exempliied in terms of its preferred modifications, it is understood that various changes may be made without departing from the spirit and scope of the disclosure and of the claims.

I claim:

l. A process for producing a hydrocarbon product having a predetermined aniline point lower than the aniline point of the feed stock from which it is produced and in greater yield than is obtained by solvent extracting the entire hydrocarbon feed stock to said predetermined aniline point for use in the manufacture of a furnace carbon black and for the production of a paraftinic oil which comprises, dividing a gas oil feed stock of aniline point within the range of to 160 F. and boiling within the range of 450 to 750 F., into two portions, each portion having said aniline point range and said boiling point range, solvent extracting one portion of said gas oil with a solvent preferential to aromatic hydrocarbons to an aniline point of 75 to 25 F., the volume ratio of said solvent to said one portion of said gas oil being in the range of 0.5:1 to 5:1, carrying out this extraction operation at a temperature within the range of 50 to F., from this extraction operation separating an aromatic hydrocarbon oil rich phase and a paraliinic hydrocarbon oil rich phase, separating solvent from each of said phases and recycling the separated solvent to the extraction operation, recovering the solvent-free paraffinic hydrocarbon oil as a paratiinic gas oil, admixing the solvent-free aromatic hydrocarbon oil with the other portion of said gas oil feed stock and recovering this admixture as said hydrocarbon product having a predetermined aniline point lower than the aniline point of the feelcll stock from Whichit is produced and in a greater yie 2. A process for producing a hydrocarbon product having a predetermined aniline point lower than the aniline point of the feed stock from which it is produced and in a greater yield than is obtained by solvent extracting the entire hydrocarbon feed stock to said predetermined aniline point for use in the manufacture of a furnace carbon black and for the production of a paraflinic oil which comprises, dividing a gas oil feed stock of aniline point within the range of 125 to 160 F. and boiling within the range of 450 to 750 F., into two portions, each portion having said aniline point range and said boiling point range, solvent extracting one portion of said gas oil with a solvent selected from the group consisting of furfural, methyl cellosolve, nitrobenzene, and liquid sulfur dioxide to an aniline point of 75 to 25 F., the volume ratio of said solvent to said one portion of said gas oil being in the range of 0.5:1 to 5: 1, carrying out this extraction operation at a temperature within the range of 50 to 160 F., from this extraction operation separating an aromatic hydrocarbon oil rich phase and a paraiiinic hydrocarbon oil rich phase, separating solvent from each of said phases and recycling the separated solvent to the extraction operation, recovering the solvent-free paraliinic hydrocarbon oil as a paraliinic gas oil, admixing the solvent-free aromatic hydrocarbon oil with the other portion of said gas oil feed stock and recovering this admixture as said hydrocarbon product having a predetermined aniline point lower than the aniline point of the feed stock from which it is produced and in a greater yield.

3. A process for producing a hydrocarbon product having a predetermined aniline point lower than the aniline point of the feed stock from which it is produced and in a greater yield than is obtained by solvent extracting the entire hydrocarbon feed stock to said predetermined aniline point for use in the manufacture of a furnace carbon black and for the production of a parafinic oil which comprises, dividing a gas oil feed stock of aniline point within the range of 125 to l60 F. and boiling within the range of 450 to 750 F., into two portions, each portion having said aniline point range and said boiling point range, solvent extracting one portion of said gas oil with furfural to an aniline point of 75 to 25 F., the volume ratio of said furfural to said one portion of said gas oil being in the range of 0.5:1 to 5:1, carrying out this extraction operation at a temperature within the range of 50 to 160 F., from this extraction operation separating an aromatic hydrocarbon oil rich phase and a paratiinic hydrocarbon oil rich phase, separating solvent from each of References Cited in the le of this patent UNITED STATES PATENTS Nu Name mber 1,585,473

Date Edeleanu May 18, 1926 15 Number 6 Lame Date E Apr. 19, 1938 Breth et a1 Dec. 13, 1938 Whiteley Feb. 7, 1939 Ferris Mar. 21, 1939 Ragatz Oct. 1, 1940 Persyn May 11, 1943 Kiersted Apr. 11, 1944 Atwell June 26, 1945 Phillips June 29, 1948 

1. A PROCESS FOR PRODUCING A HYDROCARBON PRODUCT HAVING A PREDETERMINED ANILINE POINT LOWER THAN THE ANILINE POINT OF THE FEED STOCK FROM WHICH IT IS PRODUCED AND IN GREATER YIELD THAN IS OBTAINED BY SOLVENT EXTRACTING THE ENTIRE HYDROCARBON FEED STOCK TO SAID PREDETERMINED ANILINE POINT FOR USE IN THE MANUFACTURE OF A FURNACE CARBON BLACK AND FOR THE PRODUCTION OF A PARAFFINC OIL WHICH COMPRISES, DIVIDING A GAS OIL FEED STOCK OF ANILINE POINT WITHIN THE RANGE OF 125* TO 160* F., AND BOILING WITHIN THE RANGE OF 450* TO 750* F., INTO TWO PORTIONS, EACH PORTION HAVING SAID ANILINE POINT RANGE AND SAID BOILING POINT RANGE, SOLVENT EXTRACTING ONE PORTION OF SAID GAS OIL WITH A SOLVENT PREFERENTIAL TO AROMATIC HYDROCARBONS TO AN ANILINE POINT OF -75* TO 25* F., THE VOLUME RATIO OF SAID SOLVENT TO SAID ONE PORTION OF SAID GAS OIL BEING IN THE RANGE OF 05:1 TO 5:1, CARRYING OUT THIS EXTRACTION OPERATION AT A TEMPERATURE WITHIN THE RANGE OF 50* TO 160* F., FROM THIS EXTRACTION OPERATION SEPARATING AN AROMATIC HYDROCARBON OIL RICH PHASE AND A PARAFFINIC HYDROCARBON OIL RICH PHASE, SEPARATING SOLVENT FROM EACH OF SAID PHASES AND RECYCLING THE SEPARATED SOLVENT TO THE EXTRACTION OPERATION, RECOVERING THE SOLVENT-FREE PARAFFINIC HYDROCARBON OIL AS A PARAFFINIC GAS OIL, ADMIXING THE SOLVENT-FREE AROMATIC HYDROCARBON OIL WITH THE OTHER PORTION OF SAID GAS OIL FEED STOCK AND RECOVERING THIS ADMIXTURE AS SAID HYDROCARBON PRODUCT HAVING A PREDETERMINED ANILINE POINT LOWER THAN THE ANILINE POINT OF THE FEED STOCK FROM WHICH IT IS PRODUCED AND IN A GREATER YIELD. 